The enemies in our crosshairs? Invasive species of carp that are consuming algae at an alarming rate. Silver carp and bighead carp were initially imported from Asia to help keep southern fish farms clean by eating algae and plankton. But, in the 1970s, the carp entered the Mississippi, where they swam up river, consuming so much algae and plankton that they threaten native species by eating their food source. Each day, the carp are capable of eating more than their own body weight, which can range from 30 to 100 pounds.

The carp jump away from boat motors (see photo above), which led to an idea for creating even more powerful pulses in the water. As NextGovreports:

This is why the U.S. Geological Survey needs six new water guns, ranging in size from 80 to 200 cubic inches and weighing hundreds of pounds. Water guns like these—which will run on compressed air, nitrogen or hydraulic fluids—were originally used for seismic mapping and surveys.

The carp have avoided the areas where the guns operate in pond experiments, USGS research scientist Mark Gaikowski said. If scientists can control where the invasive carp swim in nature, they can divert the fish from prime spawning habitats to reduce the population.

"Silver carp and bighead carp use the water currents to keep their eggs afloat—that way embryos develop in the eggs as they're floating down river," Gaikowski said. The idea is to disrupt this process from the get-go.